Check engine light on when it rains

[cherrychevy]

The light comes on when it rains or when pavement is wet. Light goes off after day or 2 of dry weather. Read before it is due to an electrical or oxygen sensor connection underneath that gets wet. Had the obd code but lost it and of course light is off today. 2008 silverado 2wd 5.3l. Thanks in advance.

[m3n00b]

Can't help without a code.

[sahls01gmc]

The code is stored. Get it scanned, and it should point right to where the problem is.

[Silveradodon]

I was recently experiencing some issues like this. I was driving for a few hours in a storm. The rain was shorting something out. First when I hit my brakes the lights would dim. It just got worse and worse. Then the check air bag light came on for a second. And again a few more times. My power windows unlocked and locked a few times and my truck bogged down like it was going to shut off. I rushed to a auto parts store tested my alternator and battery and both were running good.. I checked for water in fuse boxes or anywhere it's not supposed to be. Checked for loose grounds by firewall. My third brake light had a crack in it so I recently replaced that to be safe. Not sure what can be shorting out and if this is a common issue or not.

[bmp5484]

I experienced the same thing a couple times (wet weather,engine light turns on) and when I scan it I get an evap code, can't remember exactly which one but I reset the light and its good for a long time. Only had it 2x in 170k.